svn commit: r346499 - stable/12/sys/kern

[Ian Lepore]

Author: ian
Date: Sun Apr 21 20:53:15 2019
New Revision: 346499
URL: https://svnweb.freebsd.org/changeset/base/346499

Log:
  MFC r345475-r345476
  
  r345475:
  Truncate a too-long interrupt handler name when there is only one handler.
  
  There are only 19 bytes available for the name of an interrupt plus the
  name(s) of handlers/drivers using it. There is a mechanism from the days of
  shared interrupts that replaces some of the handler names with '+' when they
  don't all fit into 19 bytes.
  
  In modern times there is typically only one device on an interrupt, but long
  device names are the norm, especially with embedded systems. Also, in systems
  with multiple interrupt controllers, the names of the interrupts themselves
  can be long. For example, 'gic0,s54: imx6_anatop0' doesn't fit, and
  replacing the device driver name with a '+' provides no useful info at all.
  
  When there is only one handler but its name was too long to fit, this
  change truncates enough leading chars of the handler name (replacing them
  with a '-' char to indicate that some chars are missing) to use all 19
  bytes, preserving the unit number typically on the end of the name. Using
  the prior example, this results in: 'gic0,s54:-6_anatop0' which provides
  plenty of info to figure out which device is involved.
  
  PR:		211946
  Reviewed by:	gonzo@ (prior version without the '-' char)
  Differential Revision:	https://reviews.freebsd.org/D19675
  
  r345476:
  Revert accidental change that should not have been included in r345475.
  I had changed this value as part of a local experiment, and neglected to
  change it back before committing the other changes.

Modified:
  stable/12/sys/kern/kern_intr.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/kern/kern_intr.c
==============================================================================
--- stable/12/sys/kern/kern_intr.c	Sun Apr 21 20:50:55 2019	(r346498)
+++ stable/12/sys/kern/kern_intr.c	Sun Apr 21 20:53:15 2019	(r346499)
@@ -209,10 +209,20 @@ intr_event_update(struct intr_event *ie)
 	}
 
 	/*
-	 * If the handler names were too long, add +'s to indicate missing
-	 * names. If we run out of room and still have +'s to add, change
-	 * the last character from a + to a *.
+	 * If there is only one handler and its name is too long, just copy in
+	 * as much of the end of the name (includes the unit number) as will
+	 * fit.  Otherwise, we have multiple handlers and not all of the names
+	 * will fit.  Add +'s to indicate missing names.  If we run out of room
+	 * and still have +'s to add, change the last character from a + to a *.
 	 */
+	if (missed == 1 && space == 1) {
+		ih = CK_SLIST_FIRST(&ie->ie_handlers);
+		missed = strlen(ie->ie_fullname) + strlen(ih->ih_name) + 2 -
+		    sizeof(ie->ie_fullname);
+		strcat(ie->ie_fullname, (missed == 0) ? " " : "-");
+		strcat(ie->ie_fullname, &ih->ih_name[missed]);
+		missed = 0;
+	}
 	last = &ie->ie_fullname[sizeof(ie->ie_fullname) - 2];
 	while (missed-- > 0) {
 		if (strlen(ie->ie_fullname) + 1 == sizeof(ie->ie_fullname)) {